Venting container for pressurized products

ABSTRACT

A container for pressurized products having an interior flexible or displaceable membrane of product-impermeable material effectively dividing the container interior into a productcontaining chamber and a pressure relief chamber. A vent device when actuated places the pressure relief chamber in communication with atmosphere which enables interior expansion of the productcontaining chamber with consequent reduction of the positive interior pressure thereof.

Unite States Patent [72] Inventors Milton Kaplow White Plains, N.Y.;

Stephen Linn, Tenafly, NJ. [21] Appl. No. 19,599 [22] .Filed Mar. 16, 11970 [45] Patented Dec. 141,11971 [73] Assignee General Foods Corporation White Plains, N.Y.

[54] VENTHNG CONTATNER FOR IPRESSURIZIED IPRUDIUCTS i8 Cllnims, 1111 Drawing Figs. 7

[52] 111.5. Ci 220/85 B, 220/44 R. 220/54, 99/171 B [51] llnt. (I1 865:! 25/00 [50] Fielld of Search 220/54, 44 R, 85 13; 222/387, 389; 206/46 B; 99/181 R, 171 B, 182; 138/27, 28, 29

[56] References Cited UNITED STATES PATENTS 3,022,923 3/1958 Hoffman 99/182 UX 3,169,670 .6/1961 4 Hrebenak et a1. 222/387 X 2,889,078 6/1959 Thomas......i... 220/85 B 3,283,946 11/1966. Stec 220/44X 3,425,593 2/1969 Kramer et 3].. 220/85 B 3,483,355 12/1969 Murdock 220/54 X Primary Examiner-M. Henson Wood, Jr.

Assistant Examiner-John .1. Love Attorneys-C. Garman Hubbard, Bruno P. Struzzi and Thomas V. Sullivan thereof.

Patented Dec. 14, 1971 3,627,111

2 Sheets-Sheet l INVENTORS MILTON KAPLOW FIG, 3 STEPHEN LINN ATTORNEYS VENTING CONTAINER FOlR PRIESS UMZED PRODUCTS BACKGROUND OF THE INVENTION This invention relates generally to containers for pressurized products and more particularly to a container suitable for packaging a carbonated food product. A food product which has been recently introduced and has been gaining wider and wider consumer acceptance is one commonly known as Slush. By this term is meant a product which in cludes flavoring agents and carbohydrate sweetening agents in an aqueous solution which when maintained at the normal freezing temperatures of ordinary home freezers, typically to F., results in a partially frozen dessert-type product consisting of a large number of small ice crystals uniformly dispersed throughout a liquid matrix.

It has been found that by inclusion in the product of an appropriate amount of a freezing point depressant and/or a viscosity modulating agent there is produced a product which may be considered bifunctional in that when maintained at normal refrigerating temperatures, slightly above freezing, it constitutes a refreshing beverage of the soft drink type and when stored at the aforesaid below freezing temperatures converts into a slush-type product having the aforesaid small, uniformly dispersed ice crystals which tend to melt in the mouth, yielding a pleasant cooling sensation upon consumptron.

Heretofore, the packaging of such a bifunctional product, particularly if carbonated, for home consumption or any type of off-premises consumption has presented problems due to the pressurized condition in which the product is stored. Any such product when packaged for home use would, of necessity, require airtight containers of sufficient structural and seal strength to withstand the positive interior pressure resulting from carbonation whereby the typical amount of CO added to the product in its liquid phase might range from 2.0 to 6.0 times the volume of the product. A liquid beverage carbonated at this level will, when its temperature is lowered to render it a partially frozen or semiliquid slush-type product, release a portion of its carbon dioxide which becomes excess with relation to the slush product and tends to increase the internal positive pressure of the container. As a result, when the container is initially punctured in the process of being opened the excess CO at the increased pressure of the container, rushes through the initial puncture carrying some of the semiliquid product with it to produce a form of gushing or squirting which is highly objectionable and a source of annoyance to the consumer. The present invention provides a container with means which avoid any such gushing or squirting of the product when the container is initially opened to gain access thereto.

SUMMARY OF THE INVENTION In accordance with the invention, an airtight container is provided with a flexible or displaceable membrane or partition which effectively divides the container interior into a product chamber and a pressure relief chamber. Preferably these chambers are disposed at or embrace a respective end of the container. The flexible or displaceable membrane effectively seals the product within the product chamber and is also preferably made of a gas-impermeable material so as to retain excess (30 released when the product is cooled to a partially frozen slushlike condition, within the product chamber.

In order to serve a bifunctional purpose, the product would be packaged when in its liquid condition and at the normal appropriate level of carbonation for a liquid with the pressure relief chamber occupying a volume corresponding to the normal head space for the product and containing air at atmospheric pressure. Preferably, the container is provided with an easy opening means actuable for venting the pressure relief chamber to atmosphere to allow escape of the air from the pressure relief chamber. Thus, the product chamber is able to expand under the influence of the positive pressure increase resulting from excess C0 released as the product is chilled to a semifrozen slushlike condition. The expansion of the product chamber in this manner reduces its positive pressure a sufficient amount as to avoid gushing or squirting when the product chamber is subsequently opened preparatory to consumption of the product. If desired, the container may also be provided with an easy opener of one type or another actuable for gaining access to the product.

It is, therefore, an object of the invention to eliminate gushing or squirting from containers of semifrozen products packaged therein under pressure.

It is a further object of the invention to provide a container for a semifrozen carbonated food product with means for preventing gushing of the product when the container is initially opened to gain access thereto.

Still further objects of the invention, together with features contributing thereto and advantages accruing therefrom, will be apparent from the following description when read in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 11 is a plan view of a container in accordance with the present invention.

FIG. 2 is a sectional view in elevation of said container taken along the line 2-2 of FIG. 1.

FIG. 3 is a bottom view of said container.

FIG. 41 is an enlarged fragmentary view of a part of FIG. 2 showing a portion of the pressure relief chamber under normal pressure conditions existing when the: product is in the liquid state of a beverage.

FIG. 5 is a view similar to FIG. 4 but showing the pressure relief chamber partly contracted under the influence of increased pressure in the product chamber resulting from the excess CO existing when the product is in a semifrozen slushlike condition.

FIG. t5 is a view similar to FIGS. 4 and 5 but showing the pressure relief chamber in its fully collapsed condition after being vented to atmosphere.

FIG. 7 is a sectional view in elevation of a container showing another embodiment of the invention.

FIG. 8 is a sectional view of a container showing still another embodiment of the invention.

FIGS. 9 and 10 are sectional views of containers illustrating yet further forms of the invention.

FIG. II is a sectional view in enlarged detail of the easy open feature of the FIG. 10 embodiment.

Referring now to the drawing and in particular to the first embodiment of the invention illustrated in FIGS. 1-6, the container may comprise a conventional cylindrical can which may be made of metal or the like having a sidewall Ill and containing a product 12. The upper end of the can is enclosed with a conventional end closure 13 which is joined in sealing engagement with the upper edges of the sidewall 11 in a double rolled seam M serving to hermetically seal the product 12 in the container.

The bottom of the container or can is enclosed by an end closure 15 similarly joined to the bottom edges of the sidewall ill in a rolled over seam 16. As can be best seen in FIGS. 46, the rolled over seam 16 also includes the edge of a flexible membrane ll? which is disposed at the bottom of the container and thus constitutes a barrier between the product 12 in the upper portion of the container and the bottom end closure 15. The membrane 117 may be formed of any suitable flexible sheet material such as plastic, rubber, or the like, any may be formed with sidewalls bent in bellows fashion so as to facilitate its collapse under conditions hereinafter described. As seen, the membrane I7 serves to define with the bottom end closure w a chamber from which the product is excluded and which may be considered a pressure relief chamber 18. In assembling the container, the bottom end closure is joined to the container sidewall 111 and membrane 17 in its extended condition and under atmospheric conditions to result in the pressure relief chamber 318 containing air at atmospheric pressure. Thus,

when product is subsequently introduced through the opposite, top end'of the container, the air trapped within the chamber 18 prevents collapse of the membrane 17 from the weight of the product and thus maintains in effect an air pocket at the bottom of the can. After the container is filled with product, in liquid form, and the top end closure 13 is joined to the sidewalls at atmospheric pressure, the air within the chamber 18 continues to support the membrane in the extended position shown in FIG. 4 as long as the product is maintained as a liquid and until interior pressure increased within the product chamber, said product chamber being that portion of the container bounded by the membrane 17, sidewall 11 and top end closure 13.

As aforementioned, the container according to the present invention is designed for packaging a product which may be considered bifunctional in that it may be consumed as a beverage in a liquid state or as a slush when maintained in a semifrozen state. When the product is packaged and sealed in the container in a liquid condition, the subsequent freezing thereof will of necessity increase the internal pressure within the container. This is largely the result, in the case of carbonated products, of the release of excess CO, from the product as it is reduced in temperature from a liquid beverage to a semifrozen slush. It is also due in part to the increase in volume in the product as a result of being changed from a liquid to a semifrozen condition. Thus the invention has application to products other than carbonated products, and either type of product is intended by the terminology pressurized product."

In FIG.'4, the pressure relief chamber 18 is shown at its normal volume which exists while the product is still in a liquid state. When the product 12 is changed, by lowering its temperature to a semifrozen state, the increase in pressure within the product chamber of the container is exerted against the pressure relief chamber causing the membrane 17 to slightly contract, as indicated in FIG. 5, to compress the air within the pressure relief chamber until its pressure equals and balances the pressure exerted thereof from the product chamber. Preferably the membrane 17 is made of a gas-impermeable material so as to prevent loss of C0, through the membrane or, conversely, introduction of air into the product chamber. Thus, if the product is to be consumed as a beverage after first being frozen, subsequent thawing will result in full reconstitution thereof with carbonation at the original level. Under the pressure conditions illustrated in FIG. 5, opening of the product chamber would result in an initial rush of CO, out of the opening with sufficient force to carry with it some of the product, thereby producing the objectionable gushing or squirting which the invention is intended to avoid. The avoidance of gushing is accomplished by venting the pressure relief chamber 18 so that it may collapse and allow the product chamber to expand to a sufficient volume as to reduce the pressure thereof to an acceptable level which will not give rise to a gushing or squirting problem.

In order to facilitate the venting of the pressure relief chamber, although any manner of puncturing same would suffice, the bottom end closure may be provided with a form of easy open device such as the pull tab 21 attached beneath the head of a drawn rivetlike projection 22 formed in the material of the end closure 15. Spreading apart the tab 21 from the surface of the closure 15 by slight manual force causes a rupture in the projection 22 which provides a vent for escape of the air trapped within the pressure relief chamber 18 whereupon, as illustrated in FIG. 6, the membrane 17 fully collapses to thus increase the volume of the product chamber and cause a corresponding reduction of the pressure within the product chamber.

With the pressure in the product chamber reduced, access may safely be had to the product chamber without risk of gushing or squirting of the product as the chamber is opened. The product chamber may be opened in any suitable manner or with any suitable device. To facilitate opening of the product chamber, the top end closure 13 may be provided with a well-known form of easy opener designed upon actuation to tearing away the entire closure surface. As shown in FIG. 1, the easy opener for the top end closure 13 may be of the whirl-away" type which comprises a pull tab 23 attached to a drawn projection 24 formed centrally of the closure and at the end of a scored rip strip 25 running outwardly and around the periphery of the closure so as, when removed, to give unobstructed access to the contained product.

FIG. 7 illustrates another embodiment of the invention wherein the pressure relief chamber 26 is fully enclosed by a membrane 27 having a shape and construction similar to that of a balloon. As shown, the neck 28 of the membrane 27 extends through a beaded opening inan otherwise conventional bottom end closure 29 and is fitted with a valve device 30. The membrane 27 may be made of plastic, rubber or similar material and the balloonlike body is extended, as shown, to its normal volume by introduction of air prior to filling the container with product 12 in its liquid state. The valve 30 may be of any conventional type, preferably molded of soft rubber or a deformable plastic and provided with an interior bore through which the trapped air may be vented by insertion of a suitable implement. Venting the air will result in collapse of the membrane 27 permitting the volume of the product chamber to increase which thereby decreases its interior pressure to avoid gushing or squirting of product for the reasons mentioned heretofore in relation to the embodiment of FIGS. l6.

In the embodiment illustrated in FIG. 8, the membrane or divider separating the interior of the container into a chamber for product 12 and a pressure relief chamber 33 is in the form of a piston 31 freely displaceable axially of the container. The piston 31 may be made of any suitable semirigid, resilient material, such as plastic or the like, and presents a substantially flat circular disclike barrier or wall extending over the major portion of the cross section of the cylindrical container and having a skirt portion 32 disposed in bearing engagement with the container sidewall l l. The piston, snugly fitted to the interior wall surface of the container, acts as a gas barrier so as to retain any excess C0,, as well as product, within the product chamber, at the same time retaining the air, present at the time the container was sealed, within the pressure relief chamber 33. If desired, the container of this embodiment may have a bottom end closure 15 provided with an easy opener 21, as in the case of the first-described embodiment.

In FIG. 8 the piston 31 may be considered as occupying the position assumed upon sealing .of the container and before generation of excess CO, asa result of partially freezing the product. When the product is subsequently partially frozen, the additional pressure created by the excess CO, will depress or displace the piston downwardly to slightly reduce the volume of the pressure relief chamber 33 compressing the air therein until its pressure equals that of the product chamber. When the easy opener 21 is actuated preparatory to consumption of the semifrozen product, substantially all the air in the pressure relief chamber will be expelled as the piston is forced down to the lower extremity of the container. The consequent expansion of the product chamber reduces its pressure sufficiently so as to avoid product gushing or squirting when an opening is made at the other end of the container into the product chamber.

FIGS. 9 and 10 illustrate further embodiments of the invention adaptable for use directly with the top end closure of the respective containers. In the embodiment of FIG. 9, the membrane or divider for defining the pressure relief chamber 35 is in the form of a flexible bag 36 secured around its upper edge 37 by any suitable adhesive to the undersurface of the top end closure 15. The bag 36 is thus suspended from the central area of the top end closure and has, if desired, a scalloped sidewall to facilitate its collapse under pressure generated by excess CO, released from the product 12 when the air contained therein is permitted to escape. In this embodiment, an easy opener 21, 22 disposed centrally of the end closure 15 may be employed for venting the pressure relief chamber 35. Access to the product may be achieved by any suitable means or container opening device effective for removing the entire end closure surface. If desired, with this embodiment of the invention an easy opener could be provided for removing the bottom end closure, not shown.

In the embodiment of FIG. 10, the dividing membrane 41 defining the pressure relief chamber 42 is of a type similar to that employed in the first described embodiment and is similarly secured with its edge in a rolled over double seam 43 by which the top end closure is joined to the sidewall of the container. Also, as in the first embodiment, the end closure l5 may be provided with an easy opener 21, 22 for the reasons and purposes heretofore fully described. In the FIG. lltl embodiment the container is designed for an easy opener of the tear tape" type and for this purpose the sidewall of the container is discontinuous and includes an upper portion Ml, best seen in FIG. Ill, joined to the top end closure l5 and disposed in overlapping, telescopic engagement with the inwardly bent upper portion &5 of the bottom sidewall section 46. The joint between sections 415, 46 is sealed by a tape 47 adhesively affixed thereto and manually removable when it is desired to open the container by separating sidewall sections 34, db to gain access to the contained product. The bottom end closure 48 may be of any suitable type. As in the case of the other embodiments, venting of pressure relief chamber 42 by actuating easy opener 21 enables membrane 41 to collapse thereby adding to the volume of the product chamber, while at the same time decreasing its pressure such as to avoid squirting or gushing of the product when an opening is thereafter made into the product chamber.

While there have been shown and described what are considered to be preferred embodiments of the invention, it should, of course, be understood that changes in form could readily be made without departing from the spirit of the invention. It is intended, therefore, that the invention be not limited to the exact forms herein shown and described nor to anything less than the whole of the invention as hereinafter claimed.

What is claimed is:

l. A container for ensealing a gas-releasing product comprising, a hermetically sealed container body fabricated from gas-impermeable rigid packaging material and shaped to present opposed end portions, an end closure in sealing engagement with said container body at each said end portion, a displaceable membrane of gas-impermeable impermeable material disposed within said container body as a gas barrier between at least a partial area of one said end closure and the remainder of said container body, said membrane dividing the interior of said container into a pressure relief chamber defined in part by said partial area of said one end closure and a product chamber defined in part by the remainder of said container body, said membrane being displaceable toward said partial area of said one end closure under influence of pressure developed by gas released from said product to maintain equal gas pressure in said chambers, while said container remains sealed, and to increase the area of said product chamber after said pressure relief chamber is opened venting same to atmosphere, an easy open member formed on said end closure and manually actuable for venting said pressure relief chamber to atmosphere, and an easy open member formed on said other end closure and manually actuable to remove a substantial portion of said other end closure to enable access to said product chamber.

2. A container for ensealing a gas-releasing product comprising, a hermetically sealed container body fabricated from gas-impermeable rigid packaging material and cylindrically shaped to present opposed end pontions an end closure in sealing engagement with said container body at each said end portion, at least one of said end closures being joined to said container body in a rolled over seam, and a displaceable membrane of gas-impermeable material secured within said seam and disposed within said container body as a gas barrier between at least a partial area of said one end closure and the remainder of said container body, said membrane dividing the interior of said container into a pressure relief chamber defined in part by said partial area of said one end closure and a product chamber defined by the remainder of said container body, said membrane being displaceable toward said partial area of said one end closure under the influence of pressure developed by gas released from said product to maintain equal gas pressure in said chambers, while said container remains sealed, and to increase the area of said product chamber after said pressure relief chamber is opened venting same to atmosphere, said container body being divided into a top section joined to said one end closure at said seam and a bottom section sealed by another end closure, said top and bottom sections fitting together telescopically and including a tape adhesively applied over the seam between said top and bottom sections.

3. A package adapted to contain a pressurized product comprising, a hermetically sealed container body fabricated from gas-impermeable rigid packaging material and shaped to present opposed end portions, a displaceable membrane of gas-impermeable material disposed across said container body as a gas barrier between said end portions, said membrane dividing the interior of said container body into an air filled pressure relief chamber defined in part by one of said end portions and a product chamber defined in part by another end portion, and a gas-releasing product substantially filling said product chamber, said membrane being displaceable toward said one end portion under influence of pressure developed by gas released from said product to maintain equal gas pressure in said chambers, while said container remains sealed, and to increase the area of said product chamber after said pressure relief chamber is opened venting the air contained therein to atmosphere.

4. The invention according to claim 3 wherein said container body is cylindrical and said one end portion includes an end closure adapted to be manually ruptured to facilitate venting said pressure relief chamber to atmosphere.

5. The invention according to claim 4 wherein said another end portion includes an end closure adapted to be manually removed to facilitate access to said product chamber.

6. The invention according to claim 3 wherein said container body is cylindrical and said membrane is in the form of a piston having a skirt fitted to engage circumferentially the sidewall of said container body.

7. The invention according to claim 3 wherein said con tainer body is cylindrical and said one end portion includes an end closure joined to said container body in a rolled over seam, said membrane also being secured to said container body by said rolled over seam.

8. The invention according to claim 3 wherein said membrane is balloon shaped and disposed with a neck extending through the container body at said one end portion, said neck being' fitted with a valve to enable venting of said balloonshaped pressure relief chamber to atmosphere.

l 'l l l i 

1. A container for ensealing a gas-releasing product comprising, a hermetically sealed container body fabricated from gasimpermeable rigid packaging material and shaped to present opposed end portions, an end closure in sealing engagement with said container body at each said end portion, a displaceable membrane of gas impermeable material disposed within said container body as a gas barrier between at least a partial area of one said end closure and the remainder of said container body, said membrane dividing the interior of said container into a pressure relief chamber defined in part by said partial area of said one end closure and a product chamber defined in part by the remainder of said container body, said membrane being displaceable toward said partial area of said one end closure under influence of pressure developed by gas released from said product to maintain equal gas pressure in said chambers, while said container remains sealed, and to increase the area of said product chamber after said pressure relief chamber is opened venting same to atmosphere, an easy open member formed on said end closure and manually actuable for venting said pressure relief chamber to atmosphere, and an easy open member formed on said other end closure and manually actuable to remove a substantial portion of said other end closure to enable access to said product chamber.
 2. A container for ensealing a gas-releasing product comprising, a hermetically sealed container body fabricated from gas-impermeable rigid packaging material and cylindrically shaped to present opposed end portions, an end closure in sealing engagement with said container body at each said end portion, at least one of said end closures being joined to said container body in a rolled over seam, and a displaceable membrane of gas-impermeable material secured within said seam and disposed within said container body as a gas barrier between at least a partial area of said one end closure and the remainder of said container body, said membrane dividing the interior of said container into a pressure relief chamber defined in part by said partial area of said one end closure and a product chamber defined by the remainder of said container body, said membrane being displaceable toward said partial area of said one end closure under the influence of pressure developed by gas released from said product to maintain equal gas pressure in said chambers, while said container remains sealed, and to increase the area of said product chamber after said pressure relief chamber is opened venting same to atmosphere, said container body being divided into a top section joined to said one end closure at said seam and a bottom section sealed by another end closure, said top and bottom sections fitting together telescopically and including a tape adhesively applied over the seam between said top and bottom sections.
 3. A package adapted to contain a pressurized product comprising, a hermetically sealed container body fabricated from gas-impermeable rigid packaging material and shaped to present opposed end portions, a displaceable membrane of gas-impermeable material disposed across said container body as a gas barrier between said end portions, said membrane dividing the interior of said container body into an air filled pressure relief chamber defined in part by one of said end portions and a product chamber defined in part by another end portion, and a gas-releasing product substantially filling said product chamber, said membrane being displaceable toward said one end portion under influence of pressure developed by gas released from said product to maintain equal gas pressure in said chambers, while said container remains sealed, and to increase the area of said product chamber after said pressure relief chamber is opened venting the air contained therein to atmosphere.
 4. The invenTion according to claim 3 wherein said container body is cylindrical and said one end portion includes an end closure adapted to be manually ruptured to facilitate venting said pressure relief chamber to atmosphere.
 5. The invention according to claim 4 wherein said another end portion includes an end closure adapted to be manually removed to facilitate access to said product chamber.
 6. The invention according to claim 3 wherein said container body is cylindrical and said membrane is in the form of a piston having a skirt fitted to engage circumferentially the sidewall of said container body.
 7. The invention according to claim 3 wherein said container body is cylindrical and said one end portion includes an end closure joined to said container body in a rolled over seam, said membrane also being secured to said container body by said rolled over seam.
 8. The invention according to claim 3 wherein said membrane is balloon shaped and disposed with a neck extending through the container body at said one end portion, said neck being fitted with a valve to enable venting of said balloon-shaped pressure relief chamber to atmosphere. 